The present invention relates to short range communications systems. Specifically, an oscillator circuit is provided for generating a radio frequency carrier signal frequency modulated with a composite information signal.
A number of systems have been developed to provide short range communications such as for wireless speaker operation in a stereophonic sound reproduction system. These systems generate a low power radio frequency signal modulated with stereophonic signals in the form of right and left audio signals. The low power radio frequency signal is broadcast to a receiver connected to the speakers avoiding the necessity to hard wire the speakers to the source of stereophonic signals.
The advantage of these systems is that the speakers may be located in virtually any short range from the source of audio signals without rewiring the speakers to the source. The low power radio frequency signals are in a frequency range of 900-928 MHz, as authorized by the FCC, and have a signal to noise ratio which maintains distortion at acceptable levels. Further, the devices must avoid the problem of microphonics and other adverse affects to quality. There is also the additional requirement that consumer electronics must be economical to build as price remains a significant factor in purchasing decisions.